Description of problem:
http://tagoh.fedorapeople.org/tmp/hints/abyssinicasil-autohinting.png
http://tagoh.fedorapeople.org/tmp/hints/abyssinicasil-hinting.png

Rendering with the hinting in the font looks quite broken.

You can enable the autohinting with the following rule to make it better:

<match target="font">
  <test name="family" ignore-blanks="yes">
    <string>Abyssinica SIL</string>
  </test>
  <edit name="autohint" mode="assign">
    <bool>true</bool>
  </edit>
</match>